There is a certain expense involved in raising plants & a sort of threshold, varying by age of plant, that you're unlikely to find plants priced below. Inexpensive usually = young.

80 ft. of coverage is only about 20 - 30 plants, which wouldn't really be considered a large quantity. Here is a source for 2 year liners at $66/100. There are other sources, use the words Taxus liners as the search words. If you want more mature plants, you'll need to trust to the advice of others on the forum or to good luck in finding an inexpensive source. Least expensive is likely to be a big box store, but try to find out when shipments arrive & buy ASAP after.